In the technical field of reference of the invention, numerous orientable heads are known which are arranged for supporting video-photographic equipment and for orienting same with respect to a support plane.
In particular, heads are known which are equipped with an articulated joint of the ball-and-socket type comprising a first articulated joint member on which is fixed an attachment plate for video-photographic equipment and a second articulated joint member generally equipped with a means for anchorage to a stand such as a tripod or the like.
Heads of this type, known as ball-and-socket type heads, make it possible to lock the equipment in any preferred position (typically within a solid angle) with respect to the stand. Corresponding to this wide freedom of positioning, however, is the difficulty of accurately identifying some standard positions, in particular the state of parallelism or perpendicularity with respect to the horizontal plane.
This drawback is normally remedied by the provision on the attachment plate of one or more bubble type level indicators which, however, since they need to remain easily visible even with the equipment mounted, are normally placed in a protruding position, thus increasing the overall dimensions of the head.